This invention relates to a boundary-sealing gasket which seals all around the periphery of a space which is generally rectangular in shape but which has the peculiarity that its long edges lie along different planes that are inclined to each other.
Such a gasket is encountered in some automobile engines at the valve rocker cover or camshaft cover. These valve rocker covers are typically stamped members, made to such shapes as are determined by the cylinder head or camshaft housing. However, although some valve rocker covers are completely flat and planar, others make a turn of as much as 90.degree., which may be around arcuate end portions.
Heretofore, valve rocker cover gaskets have been made from cork composition or cork and rubber compositions that have been molded and skived into sheets and then cut out; the sheets are made completely flat or planar and of uniform thickness, typically about one-eighth inch thick. Such gaskets may be satisfactory for use in a joint with opposing flat faces, but have not proved satisfactory where the long edges lie in different planes, especially where the bolt openings lie in still different planes. Leakage has tended to develop around the bolts, with serious results, since the compression load has not held. Further complications have developed where there are arcuate end portions. In other words, the problem has been that, not being able to adapt exactly to configurations which lie out of a single plane, the gasket has tended to allow some leakage of liquids such as lubricating oils.